The present invention provides a method for detecting a ground fault in a battery of a uninterrupted power supply, the battery includes at least one string with multiple battery cells, the method including the steps of defining multiple individual battery blocks of battery cells along the at least one string, performing an reference impedance measurement for the multiple individual battery blocks at a first point of time, performing a verification impedance measurement for the multiple individual battery blocks at a second point of time, evaluating a change of measured impedance between the reference impedance and the verification impedance for the multiple individual battery blocks of the at least one string, and identifying a ground fault based on a correlated change of measured impedance of the multiple individual battery blocks along the at least one string. The present invention also provides a battery management system for managing a battery of a uninterrupted power supply, which is adapted to perform the above method. The present invention further provides a UPS device and a UPS system, each of which including an above battery management system.

A device for measuring electrode potential includes a body having an insertion portion to receive a cylindrical secondary battery with a separated beaded part formed on one surface thereof, a cover covering the one surface of the body, a working electrode terminal fixed to the body; and a counter electrode terminal fixed to the body. The insertion part includes a first insertion portion, into which a cap assembly of the cylindrical secondary battery is insertable, a second insertion portion, into which a case of the cylindrical secondary battery is insertable, and a third insertion portion, into which a first electrode tab of the cylindrical secondary battery is insertable. The second insertion part includes a case insertion portion, into which the case of the cylindrical secondary battery is insertable, and an injection portion, into which an electrolyte is injectable. A reference electrode terminal is connected to the injection portion.

A device for measuring electrode potential includes a body having an insertion portion to receive a cylindrical secondary battery with a separated beaded part formed on one surface thereof, a cover covering the one surface of the body, a working electrode terminal fixed to the body; and a counter electrode terminal fixed to the body. The insertion part includes a first insertion portion, into which a cap assembly of the cylindrical secondary battery is insertable, a second insertion portion, into which a case of the cylindrical secondary battery is insertable, and a third insertion portion, into which a first electrode tab of the cylindrical secondary battery is insertable. The second insertion part includes a case insertion portion, into which the case of the cylindrical secondary battery is insertable, and an injection portion, into which an electrolyte is injectable. A reference electrode terminal is connected to the injection portion.

Disclosed is a method for producing a sensor and a battery pressure detecting sensor produced thereby, which operate in a short mode when a pressure of a standard level or more is applied, thereby preventing the breakage and ignition of a battery due to swelling. The disclosed battery pressure detecting sensor disposes a membrane sheet formed with a first accommodation hole under a conductive sheet, has a part of the conductive sheet connected to a first terminal through a first accommodation hole, and has the membrane sheet connected to a second terminal.

Disclosed is a method for producing a sensor and a battery pressure detecting sensor produced thereby, which operate in a short mode when a pressure of a standard level or more is applied, thereby preventing the breakage and ignition of a battery due to swelling. The disclosed battery pressure detecting sensor disposes a membrane sheet formed with a first accommodation hole under a conductive sheet, has a part of the conductive sheet connected to a first terminal through a first accommodation hole, and has the membrane sheet connected to a second terminal.

In an electric battery assembly plant, including a battery assembly line having a station that receives battery cells or modules to be assembled together, a measuring apparatus is configured for measuring the electrical resistance and the electrical voltage of a single battery cell or a battery module. The correct operation of the measuring apparatus is verified by arranging at least one dummy battery cell configured and sized to emulate a real battery cell, and having an electrical resistance of a predetermined value and/or including a voltage generator to generate a voltage of a strictly predetermined value at the terminals of the dummy battery cell. The dummy battery cell may then be used as a gauge to check in a simple and rapid way whether the measuring apparatus is operating correctly and reliably.

A method for calculating the process capacity at a specific temperature of a lithium secondary battery includes a correction to a process capacity (Q.sub.3) at a specific temperature (T.sub.2) is performed using a value (Q.sub.1−Q.sub.2) obtained by subtracting the charge capacity (Q.sub.2) at the time of the shipping charge from the discharge capacity (Q.sub.1) measured at a discharge temperature (T.sub.1). A system for calculating a process capacity of a lithium secondary battery is provided.

A method for calculating the process capacity at a specific temperature of a lithium secondary battery includes a correction to a process capacity (Q.sub.3) at a specific temperature (T.sub.2) is performed using a value (Q.sub.1−Q.sub.2) obtained by subtracting the charge capacity (Q.sub.2) at the time of the shipping charge from the discharge capacity (Q.sub.1) measured at a discharge temperature (T.sub.1). A system for calculating a process capacity of a lithium secondary battery is provided.

A battery characteristic estimation device including a storage medium that stores computer-readable instructions, and a processor coupled to the storage medium, the processor executing the computer-readable instructions to: acquire time-series data of at least a voltage and current of a secondary battery having a positive electrode containing a positive electrode active material and a negative electrode containing a negative electrode active material; store a reference positive electrode OCP curve, and a reference negative electrode OCP curve; convert the reference positive electrode OCP curve into a positive electrode OCP curve in accordance with a first parameter group, convert the reference negative electrode OCP curve into a negative electrode OCP curve in accordance with a second parameter group, and estimate an OCV curve on the basis of a difference between the positive electrode OCP curve and the negative electrode OCP curve; and optimize the first parameter group and the second parameter group.

A battery characteristic estimation device including a storage medium that stores computer-readable instructions, and a processor coupled to the storage medium, the processor executing the computer-readable instructions to: acquire time-series data of at least a voltage and current of a secondary battery having a positive electrode containing a positive electrode active material and a negative electrode containing a negative electrode active material; store a reference positive electrode OCP curve, and a reference negative electrode OCP curve; convert the reference positive electrode OCP curve into a positive electrode OCP curve in accordance with a first parameter group, convert the reference negative electrode OCP curve into a negative electrode OCP curve in accordance with a second parameter group, and estimate an OCV curve on the basis of a difference between the positive electrode OCP curve and the negative electrode OCP curve; and optimize the first parameter group and the second parameter group.